What I want to achieve is, using differnt PHP versions for my dev websites hosted on my NAS and played out using the nginx module. OMV could stay on the PHP 7.0.

I could guess what you are trying to do. Having two versions of php on the box means you have to make sure the OMV and the plugins are either explicitly declaring the version they need or hope they work on the newer version. This is why I recommended not putting another version on the box. I understand that the nginx plugin is easy/convenient to use (I use it too) but docker is really where this belongs.

I created a issue in the nginx git repo: github.com/OpenMediaVault-Plug…ediavault-nginx/issues/27

May be you can take a look at it. Currently I don't see any advantage of the pool config tab without he possibility to select the PHP version to use for the pool.

This is a significant change since it has to write configs differently and in different folders based on the php fpm version you would want. Since I don't think multiple versions of php should be on the box, I'm not going to make the change. Since there is very few people working on plugins, I don't think anyone else will either. Feel free to submit a pull request with the changes.

So what is the purpose of configuring a PHP pool in your plugin if you are not able to select at least the PHP version? Different execution time, upload limits, etc. isn't neccessary at all on a local NAS in my opinion to configure different pools. PHP version will be.

Since I don't think multiple versions of php should be on the box

Why not? OMV isn't touched in anyway. What should be the problem? One of the advantages of PHP FPM is the ability to execute different PHP versions.

So what is the purpose of configuring a PHP pool in your plugin if you are not able to select at least the PHP version? Different execution time, upload limits, etc. isn't neccessary at all on a local NAS in my opinion to configure different pools. PHP version will be.

The purpose is having different sites be able to run as different users and/or being able to control the resources the site is able to use on the machine. Very useful in my opinion. If you are using nginx plugin, it is probably being used for more than a local NAS.

Why not? OMV isn't touched in anyway. What should be the problem? One of the advantages of PHP FPM is the ability to execute different PHP versions.

There isn't another version of php in the debian repo. So, adding other repos can affect stability of the machine.
There is nothing to stop you installing another version on your system.
I just have no desire to add the ability to use multiple versions of php to the nginx plugin. Like I have said before, if you want to submit a pull request adding the support, then I will accept that.